In the past, non-volatile semiconductor memories were in the form of read only memories (ROMs). Once data is written to a ROM, the written data can only be read out. Data could not be written to, or erased, from such devices. Recent development of erasable programmable read only memories (EPROMs) amounted to the turning point of non-volatile semiconductor memories, since they provide for full utility, as they are writable, readable, and erasable memories. With the benefit of compactness, low power consumption, and high stability, such non-volatile semiconductor memories have been widely applied to portable electronic equipment such as digital cameras and personal digital assistants (PDA).
In recent years, applications of non-volatile semiconductor memory devices have increased remarkably. Accordingly, there is a demand for high-speed and high-capacity non-volatile semiconductor memory devices. To utilize such non-volatile memory devices, an interface supporting a high data transfer speed is mandatory.
The “Serial Advanced Technology Attachment (ATA) Specification Version 1.1” (hereinafter referred to as “SATA”) is a form of interface standardized by the electronics industry, including APT Technology, DELL Computer, IBM, Intel, Maxtor, Seagate Technology, and so forth. The SATA interface is commonly employed in mass storage devices such as hard disk drives. SATA presently supports a first generation data transfer speed of 1.5 Gbps but is expected to support a third generation data transfer speed of 6.0 Gbps. The SATA interface has the same application level as an existing ATA interface such as extended-integrated drive electronics (E-IDE), enabling ATA-based software to operate directly in the SATA interface.